I wanted to print one of these but all others i could find just didnt work. So i made my own.
2 versions you can print. one is fully 3d printed and one has a 3/4 bearing i got off amazon.

Takes about 40 mins on my printer and a little bit of force to get everything to fit together but after its smooth and works great.

Length- 2.25"
Width- 1.25"
Hight- .75"

STEPS:
1- print
2- compress the spring so its springy (depending on your printer it might be a little harder to break free)
3- put gear on body
4- put cap on (don't put it on diagonally i made it to have a tight fit and if put on diagonally it'll not be as tight) (also cap is a little hard to get on)

SETTINGS:
Nozzle- .4mm
Infill- 15%
Infill pattern- grid
Support- none
Build plate adhesion- none
Filament- any
Size- 100%

Please give me suggestions on how to improve